Histological findings after non-ablative Er:YAG laser therapy in women with severe vaginal atrophy

Abstract

Objective: The aim of this study was to evaluate the effect of non-ablative erbium vaginal laser treatment on vaginal mucosa tissue affected by severe atrophy.

Methods: Ten patients with severe genitourinary syndrome of menopause were treated with two sessions of the non-ablative erbium-doped yttrium aluminium garnet laser (Er:YAG laser) separated by 4 weeks. Vaginal biopsies were performed before and 3 months after the second treatment. The improvement in vaginal atrophy was assessed using multiple measuring tools before and 6 months after the treatment. The degree of patients’ satisfaction was also assessed.

Results: Microscopic examination showed significant changes in the main structural components of the vaginal wall mucosa after two non-ablative Er:YAG laser sessions. The epithelial thickness increased from 45 µm (10–106 µm) to 153 µm (97–244 µm) measured 3 months after the final laser treatment. Vaginal atrophy improved in all patients by all measured outcomes. The degree of patient satisfaction was very high (3.6 on the Likert four-point scale). No adverse events or complications were observed in any of the sessions.

Conclusion: The non-ablative Er:YAG laser seems to be a safe and effective method to increase epithelial thickness of the vaginal mucosa in patients with severe vaginal atrophy.

摘要

目的：探讨非消融性铒阴道激光治疗重度阴道萎缩患者的阴道粘膜组织的疗效。

方法：对10例绝经期患有严重泌尿生殖系统综合征的患者, 采用非消融性掺铒钇铝石榴石激光器治疗, 每次治疗间隔4周。在第二次治疗前和治疗后3个月进行阴道活检。在治疗前和治疗后6个月, 应用多种检测工具评估阴道萎缩的改善情况。并对患者的满意度进行评估。

结果：经两次非消融激光照射治疗后, 阴道壁粘膜的主要结构成分发生明显改变。在激光治疗3个月后, 上皮厚度从45mm（10-106mm）增加到153mm(97-244mm）。所有检测结果显示, 所有患者的阴道萎缩都有所改善。患者满意度非常高（Likert四分制量表为3.6）。在所有疗程中均未观察到不良事件或并发症。

结论：非消融性铒：YAG激光增厚阴道粘膜是一种安全有效的方法。

Keywords:

• Genitourinary syndrome of menopause
• epithelial thickness
• vaginal laser therapy
• vaginal atrophy
• erbium laser

Introduction

Genitourinary syndrome of menopause (GSM) combines the conditions of vulvovaginal atrophy (VVA) and urinary tract dysfunction that are associated with estrogen deficiency. The syndrome may include vaginal dryness, burning, irritation, dyspareunia and urinary symptoms: urgency, dysuria, frequency and recurrent tract infections¹. All of these symptoms may interfere with sexual function and overall quality of life. GSM is associated with spontaneous or induced menopause and aging². Symptoms usually occur after the onset of menopause, with a prevalence ranging from 65% to 84%. Only 20–50% of women with GSM have symptoms and only 20–25% of symptomatic women seek medical attention³.

The aim of this study was to evaluate the effect of non-ablative vaginal laser treatment on vaginal mucosa tissue affected by severe atrophy, comparing the increase in epithelial thickness before and after the laser treatment.

Methods

This study was carried out at the Uroclinica Gynecology Service in Mendoza, Argentina and was approved by our Ethics Committee for its execution. Ten postmenopausal women aged between 50 and 70 years (average 60.6 ± 6.82 years) with duration of menopause of 10.5 ± 6.59 years (1–20 years) with severe symptoms of vaginal atrophy were included in this study (Table 1). A signed informed consent was obtained from all patients. The recruited patients had not been using any type of systemic or topical hormonal or non-hormonal therapy for the 4 months prior to the start of this study. They were treated with two sessions of non-ablative erbium-doped yttrium aluminium garnet laser (Er:YAG laser; XS Dynamis, Fotona, Slovenia) with a 250-ms SMOOTH™ pulse following a pre-established RenovaLase^® protocol^4–6 (according to the manufacturer’s instructions in the Application Manual for gynecology). The sessions were separated by 4 weeks. Potential adverse effects were monitored at every treatment and at 3 and 6 months after the second procedure.

Table 1. Patient characteristics.

Characteristics	Mean ± standard deviation	Range
Age (years)	60.6 ± 6.82	50–70
Age at menopause (years)	50.3 ± 1.9	48–55
Duration of menopause (years)	10.5 ± 6.59	1–20
Parity	1.8 ± 1.3	0–4
Body mass index (kg/m^2)	26.2 ± 1.7	23–29

Patients with recent pelvic surgery, active genital infection or a history of a collagenopathic autoimmune disease were excluded from this study.

The improvement in vaginal atrophy was assessed using a 0–10 visual analog scale (VAS) for symptoms (pain during intercourse, dryness and irritation), Vaginal Health Index Score, Female Sexual Function Index, maturation and pH values. The assessments were performed before and 6 months after the treatment.

To evaluate the epithelial thickness, biopsies under local anesthesia using injectable 2% lidocaine were taken before and 3 months after the completed treatment.

A Tischler biopsy forceps was used. The biopsy location was the middle third of the anterior vaginal wall from the right side before the treatment, and from the left side after the treatment. Biopsies were embedded in formalin and paraffin. Sections were stained with hematoxylin/eosin for a general view of the mucosal structural organization. Trichrome and PAS staining were used for more detailed examination. Microscopic observation was performed with a standard optic microscope (Primo Star, Carl Zeiss, Germany) with magnifications of 4×, 10×, and 40×.

The thickness of the vaginal epithelium was measured by counting layers of cells and calculating an average measure, with a minimum and a maximum obtained from different measurements for each sample. In addition, the glycogenic load was observed as well as the number of blood capillaries.

The subjective improvement was also assessed by evaluating the degree of satisfaction using the Likert scale, with a score from 0 to 4, where 0 is very unsatisfied, 1 is unsatisfied, 2 is neutral, 3 is satisfied and 4 is very satisfied.

Results

Positive changes were observed in all ten patients studied, resulting in a marked increase in the cellularity of the epithelium, with a greater number of layers and greater epithelial thickness that was accompanied by a significant increase in the glycogen load, new papillae, and neo-angiogenesis in the lamina propria with capillaries reaching the epithelium. The average thickness of the epithelium before treatment was 45.0 µm and varied from 10 µm (severe cases with bleeding where very few epithelial layers of cells existed) to 106 µm. In the same way, the average thickness of the epithelium after the treatment was 152.9 µm and varied from 97 µm to 244 µm (Table 2 and Figure 1)).

Figure 1. 40× magnification shows an average epithelial thickness of patient No.2 before the treatment (left picture) of 106 μm (85–120 μm) with an average of 9 (7–11) layers of cells and no glycogenic load, and after the treatment (right picture) 183 μm (160–215 μm) average of epithelial thickness with an average of 21 (15–25) layers of cells, with a significant amount of glycogen and basal cell hyperplasia.

Table 2. Patient measurement outcomes.

	Before laser treatment	6 months after final laser treatment
GSM symptoms (VAS 0–10)
Pain during intercourse	9.0 ± 0.9	1.3 ± 1.2
Dryness	8.5 ± 0.8	1.8 ± 0.8
Irritation	8.2 ± 1.2	1.8 ± 0.6
Symptoms and parameters indicating atrophy
Vaginal Health Index Score	9.3 ± 2.4	20.7 ± 1.7
Female Sexual Function Index	9.9 ± 3.6	30.1 ± 1.5
Maturation value	16.5 ± 4.7	54.0 ± 11.1
pH	5.5 ± 0.4	4.4 ± 0.5
Patient satisfaction (Likert scale 0–4)	–	3.6 ± 0.5
Thickness of endometrial epithelium	Before laser treatment	3 months after final laser treatment
Epithelial thickness (µm)	45.0 ± 33.4	152.9 ± 44.7
Number of cell layers	6.9 ± 2.4	18.9 ± 5.6

GSM, genitourinary syndrome of menopause; VAS, visual analog scale.

All observed symptoms and parameters indicating atrophy (Vaginal Health Index Score, maturation value and pH) as well as the quality of life (Female Sexual Function Index) markedly improved at the 6-month follow-up in all patients (see Table 2).

The degree of satisfaction assessed by the Likert scale was either satisfactory or very satisfactory. No adverse events or complications were observed in any of the sessions or follow-ups. The treatment was very well tolerated without anesthesia.

Discussion

GSM is characterized by changes in the quantity and quality of vaginal secretions, and loss of collagen, adipose- and water-retaining ability. The vaginal walls become thinner, less elastic and pale with a loss of rugation; the vaginal surface becomes friable with petechiae, ulcerations and bleeding often occurring after minimal trauma².

Vaginal laser therapies, such as fractional CO₂^7,8 and non-ablative erbium SMOOTH^4–6 have been established as promising treatment modalities for the management of vulvovaginal symptoms of GSM. The safety and efficacy of non-ablative erbium laser for the treatment of urinary and genital symptoms of GSM have been widely documented by several studies, both in its vaginal application and in its intraurethral application^4,5,9 but none of these papers have focused on evaluating the effect of this non-ablative erbium resurfacing at the level of the thickness of the atrophic vaginal mucosa epithelium. The published data¹⁰ include a restoration of the epithelium of the vaginal and urethral mucosa, with an increase in the epithelial turnover, greater glycogenic load, papillomatosis, collagenesis, angiogenesis and greater cellularity in the lamina propria.

The scope of this study was to measure the impact of RenovaLase^® on the level of the vaginal epithelial thickness in Argentinian women affected by symptomatic severe vaginal atrophy. In our experience, the vaginal mucosa epithelium in this type of patients (symptomatic severe vaginal atrophy) is different from those with physiologic and asymptomatic vaginal atrophy. In these severe cases, the epithelial thickness measures approximately between 5 and 100 µm. We have also observed, in cases of chorion denuded (practically without epithelium with intermittent vaginal bleeding), only two to three layers of cells per sample analyzed, with a cell size average of 6–12 µm.

The size of the cells at the level of the vaginal epithelium is not uniform and this will be in relation to the type of layer considered, the amount of glycogen, the vaginal third analyzed and the severity of the atrophy.

It is very difficult to establish in a single sample an exact measure of the epithelial thickness as well as to quantify the layers of cells and give an exact number, since the images are not three-dimensional and there will always exist overlapping layers. Thus, epithelial thickness measurements were made from several sample images and the result which was obtained was an average in micrometers and number of layers, giving a minimum and maximum.

In 2017 Lappi et al.¹⁰ treated 98 women for stress urinary incontinence with two sessions of erbium SMOOTH laser and in 18 of them performed morphometric analysis of vaginal mucosa before and 1.5–2 months after the second session. This analysis showed a 64.5% increase in epithelial thickness (from 114.19 ± 17.31 µm to 187.83 ± 15.35 µm), as well as a 61.1% increase in volume density of blood capillaries in the surface stromal layers. As the primary complaint of these patients was stress urinary incontinence, their atrophy status was not specifically reported.

Zerbinati et al.⁷ analyzed microscopic and ultrastructural modifications of atrophic vaginal mucosa after CO₂ laser treatment in five women with severe atrophy symptoms, comparing histological images before and at 1 and 2 months post laser therapy. Their findings documented the recovery of atrophic tissue, also demonstrated in thickening of the epithelium (from 5–10 to 20–40 cell layers). In 2017, Pitsouni et al.⁸ reported on their evaluation of the vaginal epithelium thickness in 26 women with severe symptoms of vaginal atrophy after three sessions of CO₂ laser. Their results before and 1 month after the last laser sessions showed an increase in the epithelial thicknesses from 125.7 ± 53.4 µm to 179.0 ± 60.8 µm.

Regarding the therapeutic effect of the laser used in our study and taking into account that the epithelial thickness measurements vary between a minimum and a maximum, we conclude that, in all the patients evaluated, the regenerative effect on the epithelium was greater than what has been observed in other published studies – in some patients, the thickness of the epithelium doubled and in others even tripled. We hypothesize that the difference in effect is due to the different mechanism of action of both technologies: the mechanism of action of all fractional ablative CO₂ lasers is the micro-wounding causing the regenerative healing process, while non-ablative Er:YAG in RenovaLase^® is using mild hyperthermia promoting vasodilation and neo-angiogenesis. Also with the fractional CO₂ approach, only about 5% of the vaginal mucosa is treated, while with the RenovaLase 100% of tissue is treated.

It is also important to notice that all observed atrophy parameters like pain, dryness, irritation, VHIS score, pH value, maturation value and FSFI scores (as presented in Table 2) showed significant improvement in trophism and in the quality of life of these patients.

Although the present study has several limitations, among them the most important being the small number of patients evaluated, it is at the same time, to our knowledge, the first study with non-ablative Er:YAG laser that evaluates changes in epithelial thickness of the vaginal mucosa in patients with severe vaginal atrophy.

Conclusion

Non-ablative Er:YAG laser seems to be a safe and effective method to increase the epithelial thickness of the vaginal mucosa in patients with severe vaginal atrophy.

Potential conflict of interest

Z. Vizintin is an employee of Fotona d.o.o.

Source of funding

Nil.